aboutsummaryrefslogtreecommitdiff
path: root/mesalib/src/mesa/main/bufferobj.c
blob: 48edd89c93df314289f5c379445618bf13635fad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
/*
 * Mesa 3-D graphics library
 * Version:  7.6
 *
 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


/**
 * \file bufferobj.c
 * \brief Functions for the GL_ARB_vertex/pixel_buffer_object extensions.
 * \author Brian Paul, Ian Romanick
 */


#include "glheader.h"
#include "enums.h"
#include "hash.h"
#include "imports.h"
#include "image.h"
#include "context.h"
#include "bufferobj.h"
#include "fbobject.h"
#include "mfeatures.h"
#include "mtypes.h"
#include "texobj.h"
#include "transformfeedback.h"
#include "dispatch.h"


/* Debug flags */
/*#define VBO_DEBUG*/
/*#define BOUNDS_CHECK*/


/**
 * Used as a placeholder for buffer objects between glGenBuffers() and
 * glBindBuffer() so that glIsBuffer() can work correctly.
 */
static struct gl_buffer_object DummyBufferObject;


/**
 * Return pointer to address of a buffer object target.
 * \param ctx  the GL context
 * \param target  the buffer object target to be retrieved.
 * \return   pointer to pointer to the buffer object bound to \c target in the
 *           specified context or \c NULL if \c target is invalid.
 */
static inline struct gl_buffer_object **
get_buffer_target(struct gl_context *ctx, GLenum target)
{
   switch (target) {
   case GL_ARRAY_BUFFER_ARB:
      return &ctx->Array.ArrayBufferObj;
   case GL_ELEMENT_ARRAY_BUFFER_ARB:
      return &ctx->Array.ArrayObj->ElementArrayBufferObj;
   case GL_PIXEL_PACK_BUFFER_EXT:
      return &ctx->Pack.BufferObj;
   case GL_PIXEL_UNPACK_BUFFER_EXT:
      return &ctx->Unpack.BufferObj;
   case GL_COPY_READ_BUFFER:
      return &ctx->CopyReadBuffer;
   case GL_COPY_WRITE_BUFFER:
      return &ctx->CopyWriteBuffer;
#if FEATURE_EXT_transform_feedback
   case GL_TRANSFORM_FEEDBACK_BUFFER:
      if (ctx->Extensions.EXT_transform_feedback) {
         return &ctx->TransformFeedback.CurrentBuffer;
      }
      break;
#endif
   case GL_TEXTURE_BUFFER:
      if (ctx->Extensions.ARB_texture_buffer_object) {
         return &ctx->Texture.BufferObject;
      }
      break;
   case GL_UNIFORM_BUFFER:
      if (ctx->Extensions.ARB_uniform_buffer_object) {
         return &ctx->UniformBuffer;
      }
      break;
   default:
      return NULL;
   }
   return NULL;
}


/**
 * Get the buffer object bound to the specified target in a GL context.
 * \param ctx  the GL context
 * \param target  the buffer object target to be retrieved.
 * \return   pointer to the buffer object bound to \c target in the
 *           specified context or \c NULL if \c target is invalid.
 */
static inline struct gl_buffer_object *
get_buffer(struct gl_context *ctx, const char *func, GLenum target)
{
   struct gl_buffer_object **bufObj = get_buffer_target(ctx, target);

   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_ENUM, "%s(target)", func);
      return NULL;
   }

   if (!_mesa_is_bufferobj(*bufObj)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "%s(buffer 0)", func);
      return NULL;
   }

   return *bufObj;
}


static inline GLbitfield
default_access_mode(const struct gl_context *ctx)
{
   /* Table 2.6 on page 31 (page 44 of the PDF) of the OpenGL 1.5 spec says:
    *
    * Name           Type  Initial Value  Legal Values
    * ...            ...   ...            ...
    * BUFFER_ACCESS  enum  READ_WRITE     READ_ONLY, WRITE_ONLY
    *                                     READ_WRITE
    *
    * However, table 6.8 in the GL_OES_mapbuffer extension says:
    *
    * Get Value         Type Get Command          Value          Description
    * ---------         ---- -----------          -----          -----------
    * BUFFER_ACCESS_OES Z1   GetBufferParameteriv WRITE_ONLY_OES buffer map flag
    *
    * The difference is because GL_OES_mapbuffer only supports mapping buffers
    * write-only.
    */
   return _mesa_is_gles(ctx)
      ? GL_MAP_WRITE_BIT : (GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
}


/**
 * Convert a GLbitfield describing the mapped buffer access flags
 * into one of GL_READ_WRITE, GL_READ_ONLY, or GL_WRITE_ONLY.
 */
static GLenum
simplified_access_mode(GLbitfield access)
{
   const GLbitfield rwFlags = GL_MAP_READ_BIT | GL_MAP_WRITE_BIT;
   if ((access & rwFlags) == rwFlags)
      return GL_READ_WRITE;
   if ((access & GL_MAP_READ_BIT) == GL_MAP_READ_BIT)
      return GL_READ_ONLY;
   if ((access & GL_MAP_WRITE_BIT) == GL_MAP_WRITE_BIT)
      return GL_WRITE_ONLY;
   return GL_READ_WRITE; /* this should never happen, but no big deal */
}


/**
 * Tests the subdata range parameters and sets the GL error code for
 * \c glBufferSubDataARB and \c glGetBufferSubDataARB.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param offset  Offset of the first byte of the subdata range.
 * \param size    Size, in bytes, of the subdata range.
 * \param caller  Name of calling function for recording errors.
 * \return   A pointer to the buffer object bound to \c target in the
 *           specified context or \c NULL if any of the parameter or state
 *           conditions for \c glBufferSubDataARB or \c glGetBufferSubDataARB
 *           are invalid.
 *
 * \sa glBufferSubDataARB, glGetBufferSubDataARB
 */
static struct gl_buffer_object *
buffer_object_subdata_range_good( struct gl_context * ctx, GLenum target, 
                                  GLintptrARB offset, GLsizeiptrARB size,
                                  const char *caller )
{
   struct gl_buffer_object *bufObj;

   if (size < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "%s(size < 0)", caller);
      return NULL;
   }

   if (offset < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "%s(offset < 0)", caller);
      return NULL;
   }

   bufObj = get_buffer(ctx, caller, target);
   if (!bufObj)
      return NULL;

   if (offset + size > bufObj->Size) {
      _mesa_error(ctx, GL_INVALID_VALUE,
		  "%s(offset %lu + size %lu > buffer size %lu)", caller,
                  (unsigned long) offset,
                  (unsigned long) size,
                  (unsigned long) bufObj->Size);
      return NULL;
   }
   if (_mesa_bufferobj_mapped(bufObj)) {
      /* Buffer is currently mapped */
      _mesa_error(ctx, GL_INVALID_OPERATION, "%s", caller);
      return NULL;
   }

   return bufObj;
}


/**
 * Allocate and initialize a new buffer object.
 * 
 * Default callback for the \c dd_function_table::NewBufferObject() hook.
 */
static struct gl_buffer_object *
_mesa_new_buffer_object( struct gl_context *ctx, GLuint name, GLenum target )
{
   struct gl_buffer_object *obj;

   (void) ctx;

   obj = MALLOC_STRUCT(gl_buffer_object);
   _mesa_initialize_buffer_object(ctx, obj, name, target);
   return obj;
}


/**
 * Delete a buffer object.
 * 
 * Default callback for the \c dd_function_table::DeleteBuffer() hook.
 */
static void
_mesa_delete_buffer_object(struct gl_context *ctx,
                           struct gl_buffer_object *bufObj)
{
   (void) ctx;

   if (bufObj->Data)
      free(bufObj->Data);

   /* assign strange values here to help w/ debugging */
   bufObj->RefCount = -1000;
   bufObj->Name = ~0;

   _glthread_DESTROY_MUTEX(bufObj->Mutex);
   free(bufObj);
}



/**
 * Set ptr to bufObj w/ reference counting.
 * This is normally only called from the _mesa_reference_buffer_object() macro
 * when there's a real pointer change.
 */
void
_mesa_reference_buffer_object_(struct gl_context *ctx,
                               struct gl_buffer_object **ptr,
                               struct gl_buffer_object *bufObj)
{
   if (*ptr) {
      /* Unreference the old buffer */
      GLboolean deleteFlag = GL_FALSE;
      struct gl_buffer_object *oldObj = *ptr;

      _glthread_LOCK_MUTEX(oldObj->Mutex);
      ASSERT(oldObj->RefCount > 0);
      oldObj->RefCount--;
#if 0
      printf("BufferObj %p %d DECR to %d\n",
             (void *) oldObj, oldObj->Name, oldObj->RefCount);
#endif
      deleteFlag = (oldObj->RefCount == 0);
      _glthread_UNLOCK_MUTEX(oldObj->Mutex);

      if (deleteFlag) {

         /* some sanity checking: don't delete a buffer still in use */
#if 0
         /* unfortunately, these tests are invalid during context tear-down */
	 ASSERT(ctx->Array.ArrayBufferObj != bufObj);
	 ASSERT(ctx->Array.ArrayObj->ElementArrayBufferObj != bufObj);
	 ASSERT(ctx->Array.ArrayObj->Vertex.BufferObj != bufObj);
#endif

	 ASSERT(ctx->Driver.DeleteBuffer);
         ctx->Driver.DeleteBuffer(ctx, oldObj);
      }

      *ptr = NULL;
   }
   ASSERT(!*ptr);

   if (bufObj) {
      /* reference new buffer */
      _glthread_LOCK_MUTEX(bufObj->Mutex);
      if (bufObj->RefCount == 0) {
         /* this buffer's being deleted (look just above) */
         /* Not sure this can every really happen.  Warn if it does. */
         _mesa_problem(NULL, "referencing deleted buffer object");
         *ptr = NULL;
      }
      else {
         bufObj->RefCount++;
#if 0
         printf("BufferObj %p %d INCR to %d\n",
                (void *) bufObj, bufObj->Name, bufObj->RefCount);
#endif
         *ptr = bufObj;
      }
      _glthread_UNLOCK_MUTEX(bufObj->Mutex);
   }
}


/**
 * Initialize a buffer object to default values.
 */
void
_mesa_initialize_buffer_object( struct gl_context *ctx,
				struct gl_buffer_object *obj,
				GLuint name, GLenum target )
{
   (void) target;

   memset(obj, 0, sizeof(struct gl_buffer_object));
   _glthread_INIT_MUTEX(obj->Mutex);
   obj->RefCount = 1;
   obj->Name = name;
   obj->Usage = GL_STATIC_DRAW_ARB;
   obj->AccessFlags = default_access_mode(ctx);
}



/**
 * Callback called from _mesa_HashWalk()
 */
static void
count_buffer_size(GLuint key, void *data, void *userData)
{
   const struct gl_buffer_object *bufObj =
      (const struct gl_buffer_object *) data;
   GLuint *total = (GLuint *) userData;

   *total = *total + bufObj->Size;
}


/**
 * Compute total size (in bytes) of all buffer objects for the given context.
 * For debugging purposes.
 */
GLuint
_mesa_total_buffer_object_memory(struct gl_context *ctx)
{
   GLuint total = 0;

   _mesa_HashWalk(ctx->Shared->BufferObjects, count_buffer_size, &total);

   return total;
}


/**
 * Allocate space for and store data in a buffer object.  Any data that was
 * previously stored in the buffer object is lost.  If \c data is \c NULL,
 * memory will be allocated, but no copy will occur.
 *
 * This is the default callback for \c dd_function_table::BufferData()
 * Note that all GL error checking will have been done already.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param size    Size, in bytes, of the new data store.
 * \param data    Pointer to the data to store in the buffer object.  This
 *                pointer may be \c NULL.
 * \param usage   Hints about how the data will be used.
 * \param bufObj  Object to be used.
 *
 * \return GL_TRUE for success, GL_FALSE for failure
 * \sa glBufferDataARB, dd_function_table::BufferData.
 */
static GLboolean
_mesa_buffer_data( struct gl_context *ctx, GLenum target, GLsizeiptrARB size,
		   const GLvoid * data, GLenum usage,
		   struct gl_buffer_object * bufObj )
{
   void * new_data;

   (void) ctx; (void) target;

   new_data = _mesa_realloc( bufObj->Data, bufObj->Size, size );
   if (new_data) {
      bufObj->Data = (GLubyte *) new_data;
      bufObj->Size = size;
      bufObj->Usage = usage;

      if (data) {
	 memcpy( bufObj->Data, data, size );
      }

      return GL_TRUE;
   }
   else {
      return GL_FALSE;
   }
}


/**
 * Replace data in a subrange of buffer object.  If the data range
 * specified by \c size + \c offset extends beyond the end of the buffer or
 * if \c data is \c NULL, no copy is performed.
 *
 * This is the default callback for \c dd_function_table::BufferSubData()
 * Note that all GL error checking will have been done already.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param offset  Offset of the first byte to be modified.
 * \param size    Size, in bytes, of the data range.
 * \param data    Pointer to the data to store in the buffer object.
 * \param bufObj  Object to be used.
 *
 * \sa glBufferSubDataARB, dd_function_table::BufferSubData.
 */
static void
_mesa_buffer_subdata( struct gl_context *ctx, GLintptrARB offset,
		      GLsizeiptrARB size, const GLvoid * data,
		      struct gl_buffer_object * bufObj )
{
   (void) ctx;

   /* this should have been caught in _mesa_BufferSubData() */
   ASSERT(size + offset <= bufObj->Size);

   if (bufObj->Data) {
      memcpy( (GLubyte *) bufObj->Data + offset, data, size );
   }
}


/**
 * Retrieve data from a subrange of buffer object.  If the data range
 * specified by \c size + \c offset extends beyond the end of the buffer or
 * if \c data is \c NULL, no copy is performed.
 *
 * This is the default callback for \c dd_function_table::GetBufferSubData()
 * Note that all GL error checking will have been done already.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param offset  Offset of the first byte to be fetched.
 * \param size    Size, in bytes, of the data range.
 * \param data    Destination for data
 * \param bufObj  Object to be used.
 *
 * \sa glBufferGetSubDataARB, dd_function_table::GetBufferSubData.
 */
static void
_mesa_buffer_get_subdata( struct gl_context *ctx, GLintptrARB offset,
			  GLsizeiptrARB size, GLvoid * data,
			  struct gl_buffer_object * bufObj )
{
   (void) ctx;

   if (bufObj->Data && ((GLsizeiptrARB) (size + offset) <= bufObj->Size)) {
      memcpy( data, (GLubyte *) bufObj->Data + offset, size );
   }
}


/**
 * Default fallback for \c dd_function_table::MapBufferRange().
 * Called via glMapBufferRange().
 */
static void *
_mesa_buffer_map_range( struct gl_context *ctx, GLintptr offset,
                        GLsizeiptr length, GLbitfield access,
                        struct gl_buffer_object *bufObj )
{
   (void) ctx;
   assert(!_mesa_bufferobj_mapped(bufObj));
   /* Just return a direct pointer to the data */
   bufObj->Pointer = bufObj->Data + offset;
   bufObj->Length = length;
   bufObj->Offset = offset;
   bufObj->AccessFlags = access;
   return bufObj->Pointer;
}


/**
 * Default fallback for \c dd_function_table::FlushMappedBufferRange().
 * Called via glFlushMappedBufferRange().
 */
static void
_mesa_buffer_flush_mapped_range( struct gl_context *ctx,
                                 GLintptr offset, GLsizeiptr length,
                                 struct gl_buffer_object *obj )
{
   (void) ctx;
   (void) offset;
   (void) length;
   (void) obj;
   /* no-op */
}


/**
 * Default callback for \c dd_function_table::MapBuffer().
 *
 * The input parameters will have been already tested for errors.
 *
 * \sa glUnmapBufferARB, dd_function_table::UnmapBuffer
 */
static GLboolean
_mesa_buffer_unmap( struct gl_context *ctx, struct gl_buffer_object *bufObj )
{
   (void) ctx;
   /* XXX we might assert here that bufObj->Pointer is non-null */
   bufObj->Pointer = NULL;
   bufObj->Length = 0;
   bufObj->Offset = 0;
   bufObj->AccessFlags = 0x0;
   return GL_TRUE;
}


/**
 * Default fallback for \c dd_function_table::CopyBufferSubData().
 * Called via glCopyBufferSubData().
 */
static void
_mesa_copy_buffer_subdata(struct gl_context *ctx,
                          struct gl_buffer_object *src,
                          struct gl_buffer_object *dst,
                          GLintptr readOffset, GLintptr writeOffset,
                          GLsizeiptr size)
{
   GLubyte *srcPtr, *dstPtr;

   /* the buffers should not be mapped */
   assert(!_mesa_bufferobj_mapped(src));
   assert(!_mesa_bufferobj_mapped(dst));

   if (src == dst) {
      srcPtr = dstPtr = ctx->Driver.MapBufferRange(ctx, 0, src->Size,
						   GL_MAP_READ_BIT |
						   GL_MAP_WRITE_BIT, src);

      if (!srcPtr)
	 return;

      srcPtr += readOffset;
      dstPtr += writeOffset;
   } else {
      srcPtr = ctx->Driver.MapBufferRange(ctx, readOffset, size,
					  GL_MAP_READ_BIT, src);
      dstPtr = ctx->Driver.MapBufferRange(ctx, writeOffset, size,
					  (GL_MAP_WRITE_BIT |
					   GL_MAP_INVALIDATE_RANGE_BIT), dst);
   }

   /* Note: the src and dst regions will never overlap.  Trying to do so
    * would generate GL_INVALID_VALUE earlier.
    */
   if (srcPtr && dstPtr)
      memcpy(dstPtr, srcPtr, size);

   ctx->Driver.UnmapBuffer(ctx, src);
   if (dst != src)
      ctx->Driver.UnmapBuffer(ctx, dst);
}



/**
 * Initialize the state associated with buffer objects
 */
void
_mesa_init_buffer_objects( struct gl_context *ctx )
{
   GLuint i;

   memset(&DummyBufferObject, 0, sizeof(DummyBufferObject));
   _glthread_INIT_MUTEX(DummyBufferObject.Mutex);
   DummyBufferObject.RefCount = 1000*1000*1000; /* never delete */

   _mesa_reference_buffer_object(ctx, &ctx->Array.ArrayBufferObj,
                                 ctx->Shared->NullBufferObj);

   _mesa_reference_buffer_object(ctx, &ctx->CopyReadBuffer,
                                 ctx->Shared->NullBufferObj);
   _mesa_reference_buffer_object(ctx, &ctx->CopyWriteBuffer,
                                 ctx->Shared->NullBufferObj);

   ctx->UniformBufferBindings = calloc(ctx->Const.MaxUniformBufferBindings,
				      sizeof(*ctx->UniformBufferBindings));

   _mesa_reference_buffer_object(ctx, &ctx->UniformBuffer,
				 ctx->Shared->NullBufferObj);

   for (i = 0; i < ctx->Const.MaxUniformBufferBindings; i++) {
      _mesa_reference_buffer_object(ctx,
				    &ctx->UniformBufferBindings[i].BufferObject,
				    ctx->Shared->NullBufferObj);
      ctx->UniformBufferBindings[i].Offset = -1;
      ctx->UniformBufferBindings[i].Size = -1;
   }
}


void
_mesa_free_buffer_objects( struct gl_context *ctx )
{
   GLuint i;

   _mesa_reference_buffer_object(ctx, &ctx->Array.ArrayBufferObj, NULL);

   _mesa_reference_buffer_object(ctx, &ctx->CopyReadBuffer, NULL);
   _mesa_reference_buffer_object(ctx, &ctx->CopyWriteBuffer, NULL);

   _mesa_reference_buffer_object(ctx, &ctx->UniformBuffer, NULL);

   for (i = 0; i < ctx->Const.MaxUniformBufferBindings; i++) {
      _mesa_reference_buffer_object(ctx,
				    &ctx->UniformBufferBindings[i].BufferObject,
				    NULL);
   }

   free(ctx->UniformBufferBindings);
   ctx->UniformBufferBindings = NULL;
}


/**
 * Bind the specified target to buffer for the specified context.
 * Called by glBindBuffer() and other functions.
 */
static void
bind_buffer_object(struct gl_context *ctx, GLenum target, GLuint buffer)
{
   struct gl_buffer_object *oldBufObj;
   struct gl_buffer_object *newBufObj = NULL;
   struct gl_buffer_object **bindTarget = NULL;

   bindTarget = get_buffer_target(ctx, target);
   if (!bindTarget) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferARB(target 0x%x)", target);
      return;
   }

   /* Get pointer to old buffer object (to be unbound) */
   oldBufObj = *bindTarget;
   if (oldBufObj && oldBufObj->Name == buffer && !oldBufObj->DeletePending)
      return;   /* rebinding the same buffer object- no change */

   /*
    * Get pointer to new buffer object (newBufObj)
    */
   if (buffer == 0) {
      /* The spec says there's not a buffer object named 0, but we use
       * one internally because it simplifies things.
       */
      newBufObj = ctx->Shared->NullBufferObj;
   }
   else {
      /* non-default buffer object */
      newBufObj = _mesa_lookup_bufferobj(ctx, buffer);
      if (!newBufObj || newBufObj == &DummyBufferObject) {
         /* If this is a new buffer object id, or one which was generated but
          * never used before, allocate a buffer object now.
          */
         ASSERT(ctx->Driver.NewBufferObject);
         newBufObj = ctx->Driver.NewBufferObject(ctx, buffer, target);
         if (!newBufObj) {
            _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBindBufferARB");
            return;
         }
         _mesa_HashInsert(ctx->Shared->BufferObjects, buffer, newBufObj);
      }
   }
   
   /* bind new buffer */
   _mesa_reference_buffer_object(ctx, bindTarget, newBufObj);

   /* Pass BindBuffer call to device driver */
   if (ctx->Driver.BindBuffer)
      ctx->Driver.BindBuffer( ctx, target, newBufObj );
}


/**
 * Update the default buffer objects in the given context to reference those
 * specified in the shared state and release those referencing the old 
 * shared state.
 */
void
_mesa_update_default_objects_buffer_objects(struct gl_context *ctx)
{
   /* Bind the NullBufferObj to remove references to those
    * in the shared context hash table.
    */
   bind_buffer_object( ctx, GL_ARRAY_BUFFER_ARB, 0);
   bind_buffer_object( ctx, GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
   bind_buffer_object( ctx, GL_PIXEL_PACK_BUFFER_ARB, 0);
   bind_buffer_object( ctx, GL_PIXEL_UNPACK_BUFFER_ARB, 0);
}



/**
 * Return the gl_buffer_object for the given ID.
 * Always return NULL for ID 0.
 */
struct gl_buffer_object *
_mesa_lookup_bufferobj(struct gl_context *ctx, GLuint buffer)
{
   if (buffer == 0)
      return NULL;
   else
      return (struct gl_buffer_object *)
         _mesa_HashLookup(ctx->Shared->BufferObjects, buffer);
}


/**
 * If *ptr points to obj, set ptr = the Null/default buffer object.
 * This is a helper for buffer object deletion.
 * The GL spec says that deleting a buffer object causes it to get
 * unbound from all arrays in the current context.
 */
static void
unbind(struct gl_context *ctx,
       struct gl_buffer_object **ptr,
       struct gl_buffer_object *obj)
{
   if (*ptr == obj) {
      _mesa_reference_buffer_object(ctx, ptr, ctx->Shared->NullBufferObj);
   }
}


/**
 * Plug default/fallback buffer object functions into the device
 * driver hooks.
 */
void
_mesa_init_buffer_object_functions(struct dd_function_table *driver)
{
   /* GL_ARB_vertex/pixel_buffer_object */
   driver->NewBufferObject = _mesa_new_buffer_object;
   driver->DeleteBuffer = _mesa_delete_buffer_object;
   driver->BindBuffer = NULL;
   driver->BufferData = _mesa_buffer_data;
   driver->BufferSubData = _mesa_buffer_subdata;
   driver->GetBufferSubData = _mesa_buffer_get_subdata;
   driver->UnmapBuffer = _mesa_buffer_unmap;

   /* GL_ARB_map_buffer_range */
   driver->MapBufferRange = _mesa_buffer_map_range;
   driver->FlushMappedBufferRange = _mesa_buffer_flush_mapped_range;

   /* GL_ARB_copy_buffer */
   driver->CopyBufferSubData = _mesa_copy_buffer_subdata;
}



/**********************************************************************/
/* API Functions                                                      */
/**********************************************************************/

void GLAPIENTRY
_mesa_BindBufferARB(GLenum target, GLuint buffer)
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glBindBuffer(%s, %u)\n",
                  _mesa_lookup_enum_by_nr(target), buffer);

   bind_buffer_object(ctx, target, buffer);
}


/**
 * Delete a set of buffer objects.
 * 
 * \param n      Number of buffer objects to delete.
 * \param ids    Array of \c n buffer object IDs.
 */
void GLAPIENTRY
_mesa_DeleteBuffersARB(GLsizei n, const GLuint *ids)
{
   GET_CURRENT_CONTEXT(ctx);
   GLsizei i;
   ASSERT_OUTSIDE_BEGIN_END(ctx);
   FLUSH_VERTICES(ctx, 0);

   if (n < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glDeleteBuffersARB(n)");
      return;
   }

   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);

   for (i = 0; i < n; i++) {
      struct gl_buffer_object *bufObj = _mesa_lookup_bufferobj(ctx, ids[i]);
      if (bufObj) {
         struct gl_array_object *arrayObj = ctx->Array.ArrayObj;
         GLuint j;

         ASSERT(bufObj->Name == ids[i] || bufObj == &DummyBufferObject);

         if (_mesa_bufferobj_mapped(bufObj)) {
            /* if mapped, unmap it now */
            ctx->Driver.UnmapBuffer(ctx, bufObj);
            bufObj->AccessFlags = default_access_mode(ctx);
            bufObj->Pointer = NULL;
         }

         /* unbind any vertex pointers bound to this buffer */
         for (j = 0; j < Elements(arrayObj->VertexAttrib); j++) {
            unbind(ctx, &arrayObj->VertexAttrib[j].BufferObj, bufObj);
         }

         if (ctx->Array.ArrayBufferObj == bufObj) {
            _mesa_BindBufferARB( GL_ARRAY_BUFFER_ARB, 0 );
         }
         if (arrayObj->ElementArrayBufferObj == bufObj) {
            _mesa_BindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, 0 );
         }

         /* unbind ARB_copy_buffer binding points */
         if (ctx->CopyReadBuffer == bufObj) {
            _mesa_BindBufferARB( GL_COPY_READ_BUFFER, 0 );
         }
         if (ctx->CopyWriteBuffer == bufObj) {
            _mesa_BindBufferARB( GL_COPY_WRITE_BUFFER, 0 );
         }

         /* unbind transform feedback binding points */
         if (ctx->TransformFeedback.CurrentBuffer == bufObj) {
            _mesa_BindBufferARB( GL_TRANSFORM_FEEDBACK_BUFFER, 0 );
         }
         for (j = 0; j < MAX_FEEDBACK_BUFFERS; j++) {
            if (ctx->TransformFeedback.CurrentObject->Buffers[j] == bufObj) {
               _mesa_BindBufferBase( GL_TRANSFORM_FEEDBACK_BUFFER, j, 0 );
            }
         }

         if (ctx->UniformBuffer == bufObj) {
            _mesa_BindBufferARB( GL_UNIFORM_BUFFER, 0 );
         }

         /* unbind any pixel pack/unpack pointers bound to this buffer */
         if (ctx->Pack.BufferObj == bufObj) {
            _mesa_BindBufferARB( GL_PIXEL_PACK_BUFFER_EXT, 0 );
         }
         if (ctx->Unpack.BufferObj == bufObj) {
            _mesa_BindBufferARB( GL_PIXEL_UNPACK_BUFFER_EXT, 0 );
         }

         if (ctx->Texture.BufferObject == bufObj) {
            _mesa_BindBufferARB( GL_TEXTURE_BUFFER, 0 );
         }

         /* The ID is immediately freed for re-use */
         _mesa_HashRemove(ctx->Shared->BufferObjects, ids[i]);
         /* Make sure we do not run into the classic ABA problem on bind.
          * We don't want to allow re-binding a buffer object that's been
          * "deleted" by glDeleteBuffers().
          *
          * The explicit rebinding to the default object in the current context
          * prevents the above in the current context, but another context
          * sharing the same objects might suffer from this problem.
          * The alternative would be to do the hash lookup in any case on bind
          * which would introduce more runtime overhead than this.
          */
         bufObj->DeletePending = GL_TRUE;
         _mesa_reference_buffer_object(ctx, &bufObj, NULL);
      }
   }

   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
}


/**
 * Generate a set of unique buffer object IDs and store them in \c buffer.
 * 
 * \param n       Number of IDs to generate.
 * \param buffer  Array of \c n locations to store the IDs.
 */
void GLAPIENTRY
_mesa_GenBuffersARB(GLsizei n, GLuint *buffer)
{
   GET_CURRENT_CONTEXT(ctx);
   GLuint first;
   GLint i;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glGenBuffers(%d)\n", n);

   if (n < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glGenBuffersARB");
      return;
   }

   if (!buffer) {
      return;
   }

   /*
    * This must be atomic (generation and allocation of buffer object IDs)
    */
   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);

   first = _mesa_HashFindFreeKeyBlock(ctx->Shared->BufferObjects, n);

   /* Insert the ID and pointer to dummy buffer object into hash table */
   for (i = 0; i < n; i++) {
      _mesa_HashInsert(ctx->Shared->BufferObjects, first + i,
                       &DummyBufferObject);
      buffer[i] = first + i;
   }

   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
}


/**
 * Determine if ID is the name of a buffer object.
 * 
 * \param id  ID of the potential buffer object.
 * \return  \c GL_TRUE if \c id is the name of a buffer object, 
 *          \c GL_FALSE otherwise.
 */
GLboolean GLAPIENTRY
_mesa_IsBufferARB(GLuint id)
{
   struct gl_buffer_object *bufObj;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);

   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
   bufObj = _mesa_lookup_bufferobj(ctx, id);
   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);

   return bufObj && bufObj != &DummyBufferObject;
}


void GLAPIENTRY
_mesa_BufferDataARB(GLenum target, GLsizeiptrARB size,
                    const GLvoid * data, GLenum usage)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glBufferData(%s, %ld, %p, %s)\n",
                  _mesa_lookup_enum_by_nr(target),
                  (long int) size, data,
                  _mesa_lookup_enum_by_nr(usage));

   if (size < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glBufferDataARB(size < 0)");
      return;
   }

   switch (usage) {
   case GL_STREAM_DRAW_ARB:
   case GL_STREAM_READ_ARB:
   case GL_STREAM_COPY_ARB:
   case GL_STATIC_DRAW_ARB:
   case GL_STATIC_READ_ARB:
   case GL_STATIC_COPY_ARB:
   case GL_DYNAMIC_DRAW_ARB:
   case GL_DYNAMIC_READ_ARB:
   case GL_DYNAMIC_COPY_ARB:
      /* OK */
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glBufferDataARB(usage)");
      return;
   }

   bufObj = get_buffer(ctx, "glBufferDataARB", target);
   if (!bufObj)
      return;

   if (_mesa_bufferobj_mapped(bufObj)) {
      /* Unmap the existing buffer.  We'll replace it now.  Not an error. */
      ctx->Driver.UnmapBuffer(ctx, bufObj);
      bufObj->AccessFlags = default_access_mode(ctx);
      ASSERT(bufObj->Pointer == NULL);
   }  

   FLUSH_VERTICES(ctx, _NEW_BUFFER_OBJECT);

   bufObj->Written = GL_TRUE;

#ifdef VBO_DEBUG
   printf("glBufferDataARB(%u, sz %ld, from %p, usage 0x%x)\n",
                bufObj->Name, size, data, usage);
#endif

#ifdef BOUNDS_CHECK
   size += 100;
#endif

   ASSERT(ctx->Driver.BufferData);
   if (!ctx->Driver.BufferData( ctx, target, size, data, usage, bufObj )) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBufferDataARB()");
   }
}


void GLAPIENTRY
_mesa_BufferSubDataARB(GLenum target, GLintptrARB offset,
                       GLsizeiptrARB size, const GLvoid * data)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   bufObj = buffer_object_subdata_range_good( ctx, target, offset, size,
                                              "glBufferSubDataARB" );
   if (!bufObj) {
      /* error already recorded */
      return;
   }

   if (size == 0)
      return;

   bufObj->Written = GL_TRUE;

   ASSERT(ctx->Driver.BufferSubData);
   ctx->Driver.BufferSubData( ctx, offset, size, data, bufObj );
}


void GLAPIENTRY
_mesa_GetBufferSubDataARB(GLenum target, GLintptrARB offset,
                          GLsizeiptrARB size, void * data)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   bufObj = buffer_object_subdata_range_good( ctx, target, offset, size,
                                              "glGetBufferSubDataARB" );
   if (!bufObj) {
      /* error already recorded */
      return;
   }

   ASSERT(ctx->Driver.GetBufferSubData);
   ctx->Driver.GetBufferSubData( ctx, offset, size, data, bufObj );
}


void * GLAPIENTRY
_mesa_MapBufferARB(GLenum target, GLenum access)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object * bufObj;
   GLbitfield accessFlags;
   void *map;

   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, NULL);

   switch (access) {
   case GL_READ_ONLY_ARB:
      accessFlags = GL_MAP_READ_BIT;
      break;
   case GL_WRITE_ONLY_ARB:
      accessFlags = GL_MAP_WRITE_BIT;
      break;
   case GL_READ_WRITE_ARB:
      accessFlags = GL_MAP_READ_BIT | GL_MAP_WRITE_BIT;
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glMapBufferARB(access)");
      return NULL;
   }

   bufObj = get_buffer(ctx, "glMapBufferARB", target);
   if (!bufObj)
      return NULL;

   if (_mesa_bufferobj_mapped(bufObj)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glMapBufferARB(already mapped)");
      return NULL;
   }

   if (!bufObj->Size) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY,
                  "glMapBuffer(buffer size = 0)");
      return NULL;
   }

   ASSERT(ctx->Driver.MapBufferRange);
   map = ctx->Driver.MapBufferRange(ctx, 0, bufObj->Size, accessFlags, bufObj);
   if (!map) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glMapBufferARB(map failed)");
      return NULL;
   }
   else {
      /* The driver callback should have set these fields.
       * This is important because other modules (like VBO) might call
       * the driver function directly.
       */
      ASSERT(bufObj->Pointer == map);
      ASSERT(bufObj->Length == bufObj->Size);
      ASSERT(bufObj->Offset == 0);
      bufObj->AccessFlags = accessFlags;
   }

   if (access == GL_WRITE_ONLY_ARB || access == GL_READ_WRITE_ARB)
      bufObj->Written = GL_TRUE;

#ifdef VBO_DEBUG
   printf("glMapBufferARB(%u, sz %ld, access 0x%x)\n",
	  bufObj->Name, bufObj->Size, access);
   if (access == GL_WRITE_ONLY_ARB) {
      GLuint i;
      GLubyte *b = (GLubyte *) bufObj->Pointer;
      for (i = 0; i < bufObj->Size; i++)
         b[i] = i & 0xff;
   }
#endif

#ifdef BOUNDS_CHECK
   {
      GLubyte *buf = (GLubyte *) bufObj->Pointer;
      GLuint i;
      /* buffer is 100 bytes larger than requested, fill with magic value */
      for (i = 0; i < 100; i++) {
         buf[bufObj->Size - i - 1] = 123;
      }
   }
#endif

   return bufObj->Pointer;
}


GLboolean GLAPIENTRY
_mesa_UnmapBufferARB(GLenum target)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   GLboolean status = GL_TRUE;
   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);

   bufObj = get_buffer(ctx, "glUnmapBufferARB", target);
   if (!bufObj)
      return GL_FALSE;

   if (!_mesa_bufferobj_mapped(bufObj)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glUnmapBufferARB");
      return GL_FALSE;
   }

#ifdef BOUNDS_CHECK
   if (bufObj->Access != GL_READ_ONLY_ARB) {
      GLubyte *buf = (GLubyte *) bufObj->Pointer;
      GLuint i;
      /* check that last 100 bytes are still = magic value */
      for (i = 0; i < 100; i++) {
         GLuint pos = bufObj->Size - i - 1;
         if (buf[pos] != 123) {
            _mesa_warning(ctx, "Out of bounds buffer object write detected"
                          " at position %d (value = %u)\n",
                          pos, buf[pos]);
         }
      }
   }
#endif

#ifdef VBO_DEBUG
   if (bufObj->AccessFlags & GL_MAP_WRITE_BIT) {
      GLuint i, unchanged = 0;
      GLubyte *b = (GLubyte *) bufObj->Pointer;
      GLint pos = -1;
      /* check which bytes changed */
      for (i = 0; i < bufObj->Size - 1; i++) {
         if (b[i] == (i & 0xff) && b[i+1] == ((i+1) & 0xff)) {
            unchanged++;
            if (pos == -1)
               pos = i;
         }
      }
      if (unchanged) {
         printf("glUnmapBufferARB(%u): %u of %ld unchanged, starting at %d\n",
                      bufObj->Name, unchanged, bufObj->Size, pos);
      }
   }
#endif

   status = ctx->Driver.UnmapBuffer( ctx, bufObj );
   bufObj->AccessFlags = default_access_mode(ctx);
   ASSERT(bufObj->Pointer == NULL);
   ASSERT(bufObj->Offset == 0);
   ASSERT(bufObj->Length == 0);

   return status;
}


void GLAPIENTRY
_mesa_GetBufferParameterivARB(GLenum target, GLenum pname, GLint *params)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   bufObj = get_buffer(ctx, "glGetBufferParameterivARB", target);
   if (!bufObj)
      return;

   switch (pname) {
   case GL_BUFFER_SIZE_ARB:
      *params = (GLint) bufObj->Size;
      return;
   case GL_BUFFER_USAGE_ARB:
      *params = bufObj->Usage;
      return;
   case GL_BUFFER_ACCESS_ARB:
      *params = simplified_access_mode(bufObj->AccessFlags);
      return;
   case GL_BUFFER_MAPPED_ARB:
      *params = _mesa_bufferobj_mapped(bufObj);
      return;
   case GL_BUFFER_ACCESS_FLAGS:
      if (!ctx->Extensions.ARB_map_buffer_range)
         goto invalid_pname;
      *params = bufObj->AccessFlags;
      return;
   case GL_BUFFER_MAP_OFFSET:
      if (!ctx->Extensions.ARB_map_buffer_range)
         goto invalid_pname;
      *params = (GLint) bufObj->Offset;
      return;
   case GL_BUFFER_MAP_LENGTH:
      if (!ctx->Extensions.ARB_map_buffer_range)
         goto invalid_pname;
      *params = (GLint) bufObj->Length;
      return;
   default:
      ; /* fall-through */
   }

invalid_pname:
   _mesa_error(ctx, GL_INVALID_ENUM, "glGetBufferParameterivARB(pname=%s)",
               _mesa_lookup_enum_by_nr(pname));
}


/**
 * New in GL 3.2
 * This is pretty much a duplicate of GetBufferParameteriv() but the
 * GL_BUFFER_SIZE_ARB attribute will be 64-bits on a 64-bit system.
 */
void GLAPIENTRY
_mesa_GetBufferParameteri64v(GLenum target, GLenum pname, GLint64 *params)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   bufObj = get_buffer(ctx, "glGetBufferParameteri64v", target);
   if (!bufObj)
      return;

   switch (pname) {
   case GL_BUFFER_SIZE_ARB:
      *params = bufObj->Size;
      return;
   case GL_BUFFER_USAGE_ARB:
      *params = bufObj->Usage;
      return;
   case GL_BUFFER_ACCESS_ARB:
      *params = simplified_access_mode(bufObj->AccessFlags);
      return;
   case GL_BUFFER_ACCESS_FLAGS:
      if (!ctx->Extensions.ARB_map_buffer_range)
         goto invalid_pname;
      *params = bufObj->AccessFlags;
      return;
   case GL_BUFFER_MAPPED_ARB:
      *params = _mesa_bufferobj_mapped(bufObj);
      return;
   case GL_BUFFER_MAP_OFFSET:
      if (!ctx->Extensions.ARB_map_buffer_range)
         goto invalid_pname;
      *params = bufObj->Offset;
      return;
   case GL_BUFFER_MAP_LENGTH:
      if (!ctx->Extensions.ARB_map_buffer_range)
         goto invalid_pname;
      *params = bufObj->Length;
      return;
   default:
      ; /* fall-through */
   }

invalid_pname:
   _mesa_error(ctx, GL_INVALID_ENUM, "glGetBufferParameteri64v(pname=%s)",
               _mesa_lookup_enum_by_nr(pname));
}


void GLAPIENTRY
_mesa_GetBufferPointervARB(GLenum target, GLenum pname, GLvoid **params)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object * bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (pname != GL_BUFFER_MAP_POINTER_ARB) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetBufferPointervARB(pname)");
      return;
   }

   bufObj = get_buffer(ctx, "glGetBufferPointervARB", target);
   if (!bufObj)
      return;

   *params = bufObj->Pointer;
}


void GLAPIENTRY
_mesa_CopyBufferSubData(GLenum readTarget, GLenum writeTarget,
                        GLintptr readOffset, GLintptr writeOffset,
                        GLsizeiptr size)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *src, *dst;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   src = get_buffer(ctx, "glCopyBufferSubData", readTarget);
   if (!src)
      return;

   dst = get_buffer(ctx, "glCopyBufferSubData", writeTarget);
   if (!dst)
      return;

   if (_mesa_bufferobj_mapped(src)) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCopyBufferSubData(readBuffer is mapped)");
      return;
   }

   if (_mesa_bufferobj_mapped(dst)) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCopyBufferSubData(writeBuffer is mapped)");
      return;
   }

   if (readOffset < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyBufferSubData(readOffset = %d)", (int) readOffset);
      return;
   }

   if (writeOffset < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyBufferSubData(writeOffset = %d)", (int) writeOffset);
      return;
   }

   if (size < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyBufferSubData(writeOffset = %d)", (int) size);
      return;
   }

   if (readOffset + size > src->Size) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyBufferSubData(readOffset + size = %d)",
                  (int) (readOffset + size));
      return;
   }

   if (writeOffset + size > dst->Size) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyBufferSubData(writeOffset + size = %d)",
                  (int) (writeOffset + size));
      return;
   }

   if (src == dst) {
      if (readOffset + size <= writeOffset) {
         /* OK */
      }
      else if (writeOffset + size <= readOffset) {
         /* OK */
      }
      else {
         /* overlapping src/dst is illegal */
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyBufferSubData(overlapping src/dst)");
         return;
      }
   }

   ctx->Driver.CopyBufferSubData(ctx, src, dst, readOffset, writeOffset, size);
}


/**
 * See GL_ARB_map_buffer_range spec
 */
void * GLAPIENTRY
_mesa_MapBufferRange(GLenum target, GLintptr offset, GLsizeiptr length,
                     GLbitfield access)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   void *map;

   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, NULL);

   if (!ctx->Extensions.ARB_map_buffer_range) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glMapBufferRange(extension not supported)");
      return NULL;
   }

   if (offset < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glMapBufferRange(offset = %ld)", (long)offset);
      return NULL;
   }

   if (length < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glMapBufferRange(length = %ld)", (long)length);
      return NULL;
   }

   if (access & ~(GL_MAP_READ_BIT |
                  GL_MAP_WRITE_BIT |
                  GL_MAP_INVALIDATE_RANGE_BIT |
                  GL_MAP_INVALIDATE_BUFFER_BIT |
                  GL_MAP_FLUSH_EXPLICIT_BIT |
                  GL_MAP_UNSYNCHRONIZED_BIT)) {
      /* generate an error if any undefind bit is set */
      _mesa_error(ctx, GL_INVALID_VALUE, "glMapBufferRange(access)");
      return NULL;
   }

   if ((access & (GL_MAP_READ_BIT | GL_MAP_WRITE_BIT)) == 0) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glMapBufferRange(access indicates neither read or write)");
      return NULL;
   }

   if ((access & GL_MAP_READ_BIT) &&
       (access & (GL_MAP_INVALIDATE_RANGE_BIT |
                  GL_MAP_INVALIDATE_BUFFER_BIT |
                  GL_MAP_UNSYNCHRONIZED_BIT))) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glMapBufferRange(invalid access flags)");
      return NULL;
   }

   if ((access & GL_MAP_FLUSH_EXPLICIT_BIT) &&
       ((access & GL_MAP_WRITE_BIT) == 0)) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glMapBufferRange(invalid access flags)");
      return NULL;
   }

   bufObj = get_buffer(ctx, "glMapBufferRange", target);
   if (!bufObj)
      return NULL;

   if (offset + length > bufObj->Size) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glMapBufferRange(offset + length > size)");
      return NULL;
   }

   if (_mesa_bufferobj_mapped(bufObj)) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glMapBufferRange(buffer already mapped)");
      return NULL;
   }

   if (!bufObj->Size) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY,
                  "glMapBufferRange(buffer size = 0)");
      return NULL;
   }

   /* Mapping zero bytes should return a non-null pointer. */
   if (!length) {
      static long dummy = 0;
      bufObj->Pointer = &dummy;
      bufObj->Length = length;
      bufObj->Offset = offset;
      bufObj->AccessFlags = access;
      return bufObj->Pointer;
   }

   ASSERT(ctx->Driver.MapBufferRange);
   map = ctx->Driver.MapBufferRange(ctx, offset, length, access, bufObj);
   if (!map) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glMapBufferARB(map failed)");
   }
   else {
      /* The driver callback should have set all these fields.
       * This is important because other modules (like VBO) might call
       * the driver function directly.
       */
      ASSERT(bufObj->Pointer == map);
      ASSERT(bufObj->Length == length);
      ASSERT(bufObj->Offset == offset);
      ASSERT(bufObj->AccessFlags == access);
   }

   return map;
}


/**
 * See GL_ARB_map_buffer_range spec
 */
void GLAPIENTRY
_mesa_FlushMappedBufferRange(GLenum target, GLintptr offset, GLsizeiptr length)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (!ctx->Extensions.ARB_map_buffer_range) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glFlushMappedBufferRange(extension not supported)");
      return;
   }

   if (offset < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glFlushMappedBufferRange(offset = %ld)", (long)offset);
      return;
   }

   if (length < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glFlushMappedBufferRange(length = %ld)", (long)length);
      return;
   }

   bufObj = get_buffer(ctx, "glFlushMappedBufferRange", target);
   if (!bufObj)
      return;

   if (!_mesa_bufferobj_mapped(bufObj)) {
      /* buffer is not mapped */
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glFlushMappedBufferRange(buffer is not mapped)");
      return;
   }

   if ((bufObj->AccessFlags & GL_MAP_FLUSH_EXPLICIT_BIT) == 0) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glFlushMappedBufferRange(GL_MAP_FLUSH_EXPLICIT_BIT not set)");
      return;
   }

   if (offset + length > bufObj->Length) {
      _mesa_error(ctx, GL_INVALID_VALUE,
		  "glFlushMappedBufferRange(offset %ld + length %ld > mapped length %ld)",
		  (long)offset, (long)length, (long)bufObj->Length);
      return;
   }

   ASSERT(bufObj->AccessFlags & GL_MAP_WRITE_BIT);

   if (ctx->Driver.FlushMappedBufferRange)
      ctx->Driver.FlushMappedBufferRange(ctx, offset, length, bufObj);
}


#if FEATURE_APPLE_object_purgeable
static GLenum
buffer_object_purgeable(struct gl_context *ctx, GLuint name, GLenum option)
{
   struct gl_buffer_object *bufObj;
   GLenum retval;

   bufObj = _mesa_lookup_bufferobj(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectPurgeable(name = 0x%x)", name);
      return 0;
   }
   if (!_mesa_is_bufferobj(bufObj)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glObjectPurgeable(buffer 0)" );
      return 0;
   }

   if (bufObj->Purgeable) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glObjectPurgeable(name = 0x%x) is already purgeable", name);
      return GL_VOLATILE_APPLE;
   }

   bufObj->Purgeable = GL_TRUE;

   retval = GL_VOLATILE_APPLE;
   if (ctx->Driver.BufferObjectPurgeable)
      retval = ctx->Driver.BufferObjectPurgeable(ctx, bufObj, option);

   return retval;
}


static GLenum
renderbuffer_purgeable(struct gl_context *ctx, GLuint name, GLenum option)
{
   struct gl_renderbuffer *bufObj;
   GLenum retval;

   bufObj = _mesa_lookup_renderbuffer(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return 0;
   }

   if (bufObj->Purgeable) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glObjectPurgeable(name = 0x%x) is already purgeable", name);
      return GL_VOLATILE_APPLE;
   }

   bufObj->Purgeable = GL_TRUE;

   retval = GL_VOLATILE_APPLE;
   if (ctx->Driver.RenderObjectPurgeable)
      retval = ctx->Driver.RenderObjectPurgeable(ctx, bufObj, option);

   return retval;
}


static GLenum
texture_object_purgeable(struct gl_context *ctx, GLuint name, GLenum option)
{
   struct gl_texture_object *bufObj;
   GLenum retval;

   bufObj = _mesa_lookup_texture(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectPurgeable(name = 0x%x)", name);
      return 0;
   }

   if (bufObj->Purgeable) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glObjectPurgeable(name = 0x%x) is already purgeable", name);
      return GL_VOLATILE_APPLE;
   }

   bufObj->Purgeable = GL_TRUE;

   retval = GL_VOLATILE_APPLE;
   if (ctx->Driver.TextureObjectPurgeable)
      retval = ctx->Driver.TextureObjectPurgeable(ctx, bufObj, option);

   return retval;
}


GLenum GLAPIENTRY
_mesa_ObjectPurgeableAPPLE(GLenum objectType, GLuint name, GLenum option)
{
   GLenum retval;

   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, 0);

   if (name == 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectPurgeable(name = 0x%x)", name);
      return 0;
   }

   switch (option) {
   case GL_VOLATILE_APPLE:
   case GL_RELEASED_APPLE:
      /* legal */
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glObjectPurgeable(name = 0x%x) invalid option: %d",
                  name, option);
      return 0;
   }

   switch (objectType) {
   case GL_TEXTURE:
      retval = texture_object_purgeable(ctx, name, option);
      break;
   case GL_RENDERBUFFER_EXT:
      retval = renderbuffer_purgeable(ctx, name, option);
      break;
   case GL_BUFFER_OBJECT_APPLE:
      retval = buffer_object_purgeable(ctx, name, option);
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glObjectPurgeable(name = 0x%x) invalid type: %d",
                  name, objectType);
      return 0;
   }

   /* In strict conformance to the spec, we must only return VOLATILE when
    * when passed the VOLATILE option. Madness.
    *
    * XXX First fix the spec, then fix me.
    */
   return option == GL_VOLATILE_APPLE ? GL_VOLATILE_APPLE : retval;
}


static GLenum
buffer_object_unpurgeable(struct gl_context *ctx, GLuint name, GLenum option)
{
   struct gl_buffer_object *bufObj;
   GLenum retval;

   bufObj = _mesa_lookup_bufferobj(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return 0;
   }

   if (! bufObj->Purgeable) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glObjectUnpurgeable(name = 0x%x) object is "
                  " already \"unpurged\"", name);
      return 0;
   }

   bufObj->Purgeable = GL_FALSE;

   retval = option;
   if (ctx->Driver.BufferObjectUnpurgeable)
      retval = ctx->Driver.BufferObjectUnpurgeable(ctx, bufObj, option);

   return retval;
}


static GLenum
renderbuffer_unpurgeable(struct gl_context *ctx, GLuint name, GLenum option)
{
   struct gl_renderbuffer *bufObj;
   GLenum retval;

   bufObj = _mesa_lookup_renderbuffer(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return 0;
   }

   if (! bufObj->Purgeable) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glObjectUnpurgeable(name = 0x%x) object is "
                  " already \"unpurged\"", name);
      return 0;
   }

   bufObj->Purgeable = GL_FALSE;

   retval = option;
   if (ctx->Driver.RenderObjectUnpurgeable)
      retval = ctx->Driver.RenderObjectUnpurgeable(ctx, bufObj, option);

   return retval;
}


static GLenum
texture_object_unpurgeable(struct gl_context *ctx, GLuint name, GLenum option)
{
   struct gl_texture_object *bufObj;
   GLenum retval;

   bufObj = _mesa_lookup_texture(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return 0;
   }

   if (! bufObj->Purgeable) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glObjectUnpurgeable(name = 0x%x) object is"
                  " already \"unpurged\"", name);
      return 0;
   }

   bufObj->Purgeable = GL_FALSE;

   retval = option;
   if (ctx->Driver.TextureObjectUnpurgeable)
      retval = ctx->Driver.TextureObjectUnpurgeable(ctx, bufObj, option);

   return retval;
}


GLenum GLAPIENTRY
_mesa_ObjectUnpurgeableAPPLE(GLenum objectType, GLuint name, GLenum option)
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, 0);

   if (name == 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return 0;
   }

   switch (option) {
   case GL_RETAINED_APPLE:
   case GL_UNDEFINED_APPLE:
      /* legal */
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glObjectUnpurgeable(name = 0x%x) invalid option: %d",
                  name, option);
      return 0;
   }

   switch (objectType) {
   case GL_BUFFER_OBJECT_APPLE:
      return buffer_object_unpurgeable(ctx, name, option);
   case GL_TEXTURE:
      return texture_object_unpurgeable(ctx, name, option);
   case GL_RENDERBUFFER_EXT:
      return renderbuffer_unpurgeable(ctx, name, option);
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glObjectUnpurgeable(name = 0x%x) invalid type: %d",
                  name, objectType);
      return 0;
   }
}


static void
get_buffer_object_parameteriv(struct gl_context *ctx, GLuint name,
                              GLenum pname, GLint *params)
{
   struct gl_buffer_object *bufObj = _mesa_lookup_bufferobj(ctx, name);
   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glGetObjectParameteriv(name = 0x%x) invalid object", name);
      return;
   }

   switch (pname) {
   case GL_PURGEABLE_APPLE:
      *params = bufObj->Purgeable;
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glGetObjectParameteriv(name = 0x%x) invalid enum: %d",
                  name, pname);
      break;
   }
}


static void
get_renderbuffer_parameteriv(struct gl_context *ctx, GLuint name,
                             GLenum pname, GLint *params)
{
   struct gl_renderbuffer *rb = _mesa_lookup_renderbuffer(ctx, name);
   if (!rb) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return;
   }

   switch (pname) {
   case GL_PURGEABLE_APPLE:
      *params = rb->Purgeable;
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glGetObjectParameteriv(name = 0x%x) invalid enum: %d",
                  name, pname);
      break;
   }
}


static void
get_texture_object_parameteriv(struct gl_context *ctx, GLuint name,
                               GLenum pname, GLint *params)
{
   struct gl_texture_object *texObj = _mesa_lookup_texture(ctx, name);
   if (!texObj) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glObjectUnpurgeable(name = 0x%x)", name);
      return;
   }

   switch (pname) {
   case GL_PURGEABLE_APPLE:
      *params = texObj->Purgeable;
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glGetObjectParameteriv(name = 0x%x) invalid enum: %d",
                  name, pname);
      break;
   }
}


void GLAPIENTRY
_mesa_GetObjectParameterivAPPLE(GLenum objectType, GLuint name, GLenum pname,
                                GLint *params)
{
   GET_CURRENT_CONTEXT(ctx);

   if (name == 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glGetObjectParameteriv(name = 0x%x)", name);
      return;
   }

   switch (objectType) {
   case GL_TEXTURE:
      get_texture_object_parameteriv(ctx, name, pname, params);
      break;
   case GL_BUFFER_OBJECT_APPLE:
      get_buffer_object_parameteriv(ctx, name, pname, params);
      break;
   case GL_RENDERBUFFER_EXT:
      get_renderbuffer_parameteriv(ctx, name, pname, params);
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glGetObjectParameteriv(name = 0x%x) invalid type: %d",
                  name, objectType);
   }
}

#endif /* FEATURE_APPLE_object_purgeable */

static void
set_ubo_binding(struct gl_context *ctx,
		int index,
		struct gl_buffer_object *bufObj,
		GLintptr offset,
		GLsizeiptr size,
		GLboolean autoSize)
{
   struct gl_uniform_buffer_binding *binding;

   binding = &ctx->UniformBufferBindings[index];
   if (binding->BufferObject == bufObj &&
       binding->Offset == offset &&
       binding->Size == size &&
       binding->AutomaticSize == autoSize) {
      return;
   }

   FLUSH_VERTICES(ctx, _NEW_BUFFER_OBJECT);

   _mesa_reference_buffer_object(ctx, &binding->BufferObject, bufObj);
   binding->Offset = offset;
   binding->Size = size;
   binding->AutomaticSize = autoSize;
}

/**
 * Bind a region of a buffer object to a uniform block binding point.
 * \param index  the uniform buffer binding point index
 * \param bufObj  the buffer object
 * \param offset  offset to the start of buffer object region
 * \param size  size of the buffer object region
 */
static void
bind_buffer_range_uniform_buffer(struct gl_context *ctx,
				 GLuint index,
				 struct gl_buffer_object *bufObj,
				 GLintptr offset,
				 GLsizeiptr size)
{
   if (index >= ctx->Const.MaxUniformBufferBindings) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glBindBufferRange(index=%d)", index);
      return;
   }

   if (offset & (ctx->Const.UniformBufferOffsetAlignment - 1)) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glBindBufferRange(offset misalgned %d/%d)", (int) offset,
		  ctx->Const.UniformBufferOffsetAlignment);
      return;
   }

   if (bufObj == ctx->Shared->NullBufferObj) {
      offset = -1;
      size = -1;
   }

   _mesa_reference_buffer_object(ctx, &ctx->UniformBuffer, bufObj);
   set_ubo_binding(ctx, index, bufObj, offset, size, GL_FALSE);
}


/**
 * Bind a buffer object to a uniform block binding point.
 * As above, but offset = 0.
 */
static void
bind_buffer_base_uniform_buffer(struct gl_context *ctx,
				GLuint index,
				struct gl_buffer_object *bufObj)
{
   if (index >= ctx->Const.MaxUniformBufferBindings) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glBindBufferBase(index=%d)", index);
      return;
   }

   _mesa_reference_buffer_object(ctx, &ctx->UniformBuffer, bufObj);
   if (bufObj == ctx->Shared->NullBufferObj)
      set_ubo_binding(ctx, index, bufObj, -1, -1, GL_TRUE);
   else
      set_ubo_binding(ctx, index, bufObj, 0, 0, GL_TRUE);
}

void GLAPIENTRY
_mesa_BindBufferRange(GLenum target, GLuint index,
                      GLuint buffer, GLintptr offset, GLsizeiptr size)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;

   if (buffer == 0) {
      bufObj = ctx->Shared->NullBufferObj;
   } else {
      bufObj = _mesa_lookup_bufferobj(ctx, buffer);
   }

   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glBindBufferRange(invalid buffer=%u)", buffer);
      return;
   }

   if (size <= 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glBindBufferRange(size=%d)",
		  (int) size);
      return;
   }

   if (offset + size > bufObj->Size) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glBindBufferRange(offset + size %d > buffer size %d)",
		  (int) (offset + size), (int) (bufObj->Size));
      return;
   }

   switch (target) {
   case GL_TRANSFORM_FEEDBACK_BUFFER:
      _mesa_bind_buffer_range_transform_feedback(ctx, index, bufObj,
						 offset, size);
      return;
   case GL_UNIFORM_BUFFER:
      bind_buffer_range_uniform_buffer(ctx, index, bufObj, offset, size);
      return;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferRange(target)");
      return;
   }
}

void GLAPIENTRY
_mesa_BindBufferBase(GLenum target, GLuint index, GLuint buffer)
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_buffer_object *bufObj;

   if (buffer == 0) {
      bufObj = ctx->Shared->NullBufferObj;
   } else {
      bufObj = _mesa_lookup_bufferobj(ctx, buffer);
   }

   if (!bufObj) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glBindBufferBase(invalid buffer=%u)", buffer);
      return;
   }

   /* Note that there's some oddness in the GL 3.1-GL 3.3 specifications with
    * regards to BindBufferBase.  It says (GL 3.1 core spec, page 63):
    *
    *     "BindBufferBase is equivalent to calling BindBufferRange with offset
    *      zero and size equal to the size of buffer."
    *
    * but it says for glGetIntegeri_v (GL 3.1 core spec, page 230):
    *
    *     "If the parameter (starting offset or size) was not specified when the
    *      buffer object was bound, zero is returned."
    *
    * What happens if the size of the buffer changes?  Does the size of the
    * buffer at the moment glBindBufferBase was called still play a role, like
    * the first quote would imply, or is the size meaningless in the
    * glBindBufferBase case like the second quote would suggest?  The GL 4.1
    * core spec page 45 says:
    *
    *     "It is equivalent to calling BindBufferRange with offset zero, while
    *      size is determined by the size of the bound buffer at the time the
    *      binding is used."
    *
    * My interpretation is that the GL 4.1 spec was a clarification of the
    * behavior, not a change.  In particular, this choice will only make
    * rendering work in cases where it would have had undefined results.
    */

   switch (target) {
   case GL_TRANSFORM_FEEDBACK_BUFFER:
      _mesa_bind_buffer_base_transform_feedback(ctx, index, bufObj);
      return;
   case GL_UNIFORM_BUFFER:
      bind_buffer_base_uniform_buffer(ctx, index, bufObj);
      return;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferBase(target)");
      return;
   }
}

void
_mesa_init_bufferobj_dispatch(struct _glapi_table *disp)
{
   SET_BindBufferARB(disp, _mesa_BindBufferARB);
   SET_BufferDataARB(disp, _mesa_BufferDataARB);
   SET_BufferSubDataARB(disp, _mesa_BufferSubDataARB);
   SET_DeleteBuffersARB(disp, _mesa_DeleteBuffersARB);
   SET_GenBuffersARB(disp, _mesa_GenBuffersARB);
   SET_GetBufferParameterivARB(disp, _mesa_GetBufferParameterivARB);
   SET_GetBufferPointervARB(disp, _mesa_GetBufferPointervARB);
   SET_GetBufferSubDataARB(disp, _mesa_GetBufferSubDataARB);
   SET_IsBufferARB(disp, _mesa_IsBufferARB);
   SET_MapBufferARB(disp, _mesa_MapBufferARB);
   SET_UnmapBufferARB(disp, _mesa_UnmapBufferARB);
   SET_BindBufferRangeEXT(disp, _mesa_BindBufferRange);
   SET_BindBufferBaseEXT(disp, _mesa_BindBufferBase);
}